public class Test {
        public static void main(String[] args) {
            PetDog dog = new PetDog();
            dog.name = "大黄";
            dog.wag();
            dog.name = "大黑";
            dog.barks();
        }
    }

    class PetDog {
        public String name;//名字
        public String colo;//颜色
        //狗的属性
        public void barks() {
            System.out.println(name + ":汪汪汪~~~");
        }
        //狗的行为
        public void wag() {
            System.out.println(name + ":睡觉");
        }
    }

